There are several weeks left in the 2019 summer transfer window, but all of Europe's top clubs have a lot of shopping and selling left to do before they can consider themselves ready for the new campaign.

With that in mind, we asked ESPN FC's experts to canvass the big teams and get a sense of their to-do lists over the next two months. What's the biggest thing they need to tackle? Which one player could make the difference? And which players should be sold in order to make room?

Although they pulled off a domestic treble last season, City have key areas in which they need help this summer. Vincent Kompany's move into management with Anderlecht has left Pep Guardiola a man down in central defence, a long-term replacement for Fernandinho still needs to be found and City need greater cover for Sergio Aguero should the Argentine forward succumb to injury. City simply need to ensure that they take care of these issues before they potentially become problems further down the line. It is not a summer for big investment or a major rebuild but smart, strategic housekeeping instead.

Players they need to sign: City are targeting Leicester's Harry Maguire as the replacement for Kompany and Atletico Madrid midfielders Rodri and Saul Niguez have both been identified as potential solutions to the Fernandinho problem. As for a new striker to bolster their attacking options, City simply need somebody who will prove to be more reliable than Gabriel Jesus.

Players on their way out:Ilkay Gundogan is out of contract in 12 months' time and refusing to sign a new deal, while David Silva has confirmed that he will leave next summer when his contract expires.

Players they should sell:Leroy Sane may force a move to Bayern Munich after growing frustrated by his role under Guardiola, while Benjamin Mendy and Riyad Mahrez could be sold if City receive realistic offers. -- Mark Ogden

Quality rather than quantity is the mantra for Liverpool this summer, who ended last season as European champions after the four-year rebuild under Jurgen Klopp. The Liverpool squad is now strong in every department and key players have been tied down to long-term contracts. But they can be stronger at centre-half, where a commanding partner for Virgil van Dijk would make them even more formidable. Genuine creativity in midfield would also be welcomed, even though Liverpool came within a whisker of also winning the Premier League title last season.

Players they need to sign:Matthijs de Ligt would have been the perfect signing at centre-half but the Ajax defender now seems set for Juventus. A return for former playmaker Philippe Coutinho would be a good move for Liverpool.

Players on their way out: Liverpool have already offloaded Daniel Sturridge and Alberto Moreno at the end of their contracts this summer, while they could yet cash in in Dejan Lovren. Loris Karius, currently on loan at Besiktas, is another who could be sold.

Players they should sell: After two seasons of injury problems, Adam Lallana may feel vulnerable, while Nathaniel Clyne has little future at Anfield. -- Mark Ogden

Spurs simply need to make a signing having failed to boost their squad since Jan 2018. Mauricio Pochettino still managed to guide them to the Champions League final last season but for the club to take a big step forward, they have to add quality and depth to their pool of players. Every area of the squad could benefit from new blood, with Spurs arguably needing 4-5 incoming players to ensure they don't fall behind their top six rivals. Alongside the recruitment drive, Pochettino must also ensure that none of his top stars, such as Harry Kane, Heung-min Son or Dele Alli, are lured away.

Players they need to sign: Spurs have done well buying young players and low-priced signings in recent years, but they now need proven performers and stars at the top of their game to take them to the next level.

Players on their way out:Christian Eriksen has revealed he wants to leave rather than sign a new deal to replace his contract, which expires in 12 months. Kieran Trippier looks set for a move away, while Toby Alderweireld's £25 million release clause will likely see him move on too.

Players they should sell:Vincent Janssen is on his way out and Victor Wanyama could also be moved on. Eric Dier, whose progress has stalled since the World Cup, may also be offloaded. -- Mark Ogden

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Which on-loan players can have an impact at Chelsea?

ESPN FC's Craig Burley selects a few from Chelsea's famous 'loan army' that might make an impact at the club next season.

With Chelsea hit by a worldwide, two-window transfer embargo, the key is to keep departures to a minimum. Eden Hazard has already been sold to Real Madrid and Jorginho could follow him out of the door now that his great champion, Maurizio Sarri, has left Chelsea to take charge of Juventus. But with no ability to add to their squad, Chelsea simply have to keep what they have and decide whether any of their many loaned players are capable to returning to Stamford Bridge to perform at the highest level.

Players they need to sign: Unless they overturn their transfer ban, Chelsea can only draw up a hit-list for summer 2020, when they will be allowed back into the market.

Players on their way out: Hazard has already gone and Gonzalo Higuain has returned to parent club Juventus after a disappointing loan spell last season, so there is little scope for others to leave.

Players they should sell: Jorginho was signed by Sarri to make his system work, but with the Italian no longer in charge, it's difficult to see a future for the midfielder at Chelsea. -- Mark Ogden

Year 2 of the post-Arsene Wenger era needs to follow the path of the first season under Unai Emery, when Arsenal finally began to address long-standing issues in defence and midfield. Arsenal still require more quality in defensive positions and the loss of Aaron Ramsey will leave them short of goals and energy in midfield. But they have quality up front in Alexandre Lacazette and Pierre-Emerick Aubameyang, so the focus will be on tightening up at the back. The big problem will be finances, however, with Arsenal lacking the money to compete at the top of end of the market.

Players they need to sign: Arsenal need to be smart and decisive in the market due to their lack of finances. They cannot go after the expensive, ready-made signings, so it is all about finding value, and the move for Celtic's Kieran McKenna is a pointer towards the club working well within their means.

Players on their way out: Ramsey has gone to Juventus and Danny Welbeck has also been allowed to leave on a free transfer. Petr Cech's retirement leaves Arsenal needing a senior backup keeper behind Bernd Leno.

Players they should sell: Mesut Ozil has shown himself to be incompatible with Unai Emery's requirements. Selling the German would ease the wage bill and also send a message about what the coach expects from his players. -- Mark Ogden

Man United's biggest concern has to be locking down stars like David De Gea and Marcus Rashford to new long-term deals before it's too late. No pressure. Getty

United have allowed themselves to become a club with more problems than solutions. Every area of the squad needs strengthening, but big-name players like David de Gea, Paul Pogba and Romelu Lukaku are all looking for the nearest exit door. With only £100m to spend, Ole Gunnar Solskjaer has little scope to perform much-needed surgery on the squad, but any additions United make will be essential. Aside from making the squad stronger with new arrivals, United must focus on securing Marcus Rashford to a new contract and attempt to persuade De Gea to do the same.

Players they need to sign: United need to add experience and quality to the spine of their team in the hope that it makes the rest of the squad raise their game. But so far, it has been a disappointing summer in the market with little sign of significant additions being made.

Players on their way out:Antonio Valencia and Ander Herrera have gone as free agents, but the big question is whether United can hold onto Pogba and De Gea.

Players they should sell: United need to add to their squad rather than weaken it further, but the likes of Anthony Martial and Alexis Sanchez have done little to suggest they will make United a better team by staying. -- Mark Ogden

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Joao Felix to Atleti - Massive gamble or potential coup?

Sid Lowe says Atletico Madrid's offer to Benfica for Joao Felix represents a shift in their transfer strategy, but isn't convinced it will pay off.

Bob Dylan isn't a Cule but the answer, my friend, is blowing in the wind, by which I mean that anyone claiming that Barcelona's summer objectives are planned, strategic and wholly bankable wouldn't be telling the truth. Take Neymar. When, in March, FCB struck a deal with Antoine Griezmann that they'd pay his buyout clause of €120m after July 1, they didn't know Paris Saint-Germain would want to dump Neymar or that the AWOL Brazilian would go down on bended knee for a Camp Nou return. Thus, their efforts to resign him are being improvised.

There isn't a budget line, or even close to it, at Barcelona. Yeah, there's a strategy that the squad needs to be pared down, huge sums need to be earned via general sales, the top 14-15 players need to be faster, stronger and more resilient when next Spring comes than during the last four years.

Players they need to sign: An elite right-back who is tall, athletic and technically gifted if possible. Dani Alves only fulfils two of these criteria, but he is also dreaming of a Camp Nou return. Also a highly competitive left-back to both push and offer rest to Jordi Alba. They need a replacement for Jasper Cillessen replacement, presumably Neto.

Players they should sell:Ousmane Dembele? He's an extraordinary talent, albeit with Neymar-esque tendencies off the pitch, so Barcelona don't want to sell unless they're guaranteed both Griezmann and Neymar are coming in. They view their high-price-tag, saleable assets as being Coutinho plus Rakitic. The former has seen his value plummet and two possible destinations, Chelsea and Manchester United, marked "impossible." Rakitic, who has a market, steadfastly refuses to budge. Nor should they sell him if someone has to tidy up behind a front line of Suarez, Messi, Neymar and Griezmann! -- Graham Hunter

Education used to be "the three R's," reading, writing and 'rithmetic. Two "R's" sum up the title of Atleti's summer assignment, too: Rejuvenation and replacement. The trademark across Diego Simeone's eight brilliant years as manager has been a snarling, street-smart and perpetual competitive energy. Pressing, passing, prying teams open. That's been evaporating of late, and it's vital that Atleti 2019-20 become fitter, fierier, battle-ready and mean-eyed. The second principal task is compensating for a vast haemorrhage of experience. Not just Godin and Lucas Hernandez but Juanfran, Antoine Griezmann, probably Rodri and Filipe Luis too.

Players they need to sign:Mario Hermoso or Nicolas Otamendi would be good bets to bolster los Rojiblancos in precisely the way they need, albeit that the former remains a prospect and the latter is a known quantity (for better and for worse). Unless Simeone suddenly trusts Sime Vrsaljko (doubtful), Atleti need to sign a right-back and a left-back for the first team.

There's a wonderful replacement for Griezmann out there in Mikel Oyarzabal, but La Real would be mad to sell and as soon as the world knew that the Basque striker was buyable, there promises to be a big queue. It shouldn't stop Atleti trying, though. Chimy Avila showed enough at Huesca to prove that he could, if bought from San Lorenzo, be a marvellous jack-in-the-box player for Simeone: he's energetic, aggressive, competitive, quick, goal-providing and a fan favourite.

Players on their way out: The door marked Salida has been banging open so often in recent weeks that only the true "no-hopers" will be allowed to leave easily now. Gelson Martins didn't work, never looked like working and recently stated his extreme aversion to returning. He's a goner.

Players they should sell: The evidence, albeit brief, suggests that in Francisco Montero, Borja Garces, Victor Mollejo and Sergio Camello, Atleti have a very healthy batch of "kids" ready to push through. They should sell in order to, as gardeners would put it, "dead-head." Let the fresh petals bloom. Out, and good riddance, should go Diego Costa, too, as he's aging, unreliable, overweight and goal-shy. There may still be value in moving Vitolo, whose time with Atleti has been a gross disappointment. If Emery wants him at Arsenal, they should sell! -- Graham Hunter

There are a huge number of objectives on the go here. Madrid need, first, to make their squad competitive again. Last season they were paper-thin, listless, sated and easy to beat. It's imperative that the new signings, those already bought and those to come, add intensity, hunger and a "winning" mindset. Secondly, Los Blancos need to continue a huge operation aimed at both reducing the bloated squad collecting a first-team salary while, at the same time, generating a huge amount of money: at least €200m.

Finally, Zidane needs to work out a playing system that adapts well to the embarrassment of attacking and creative talent he has at his disposal. A bonus, if achievable, would be for President Florentino Perez and coach Zidane to see eye-to-eye on more matters so that the low-rumble of "would Zizou REALLY walk away again if he doesn't get his way?" dissipates and allows the focussed work to succeed.

Players they need to sign: Frankly they've done well so far. Hazard is their Galactico. We knew about Rodrygo, while Eder Militao has been sorted for some time. All three add quality, albeit with wild variances in experience. Luka Jovic will score goals anywhere if supplied with chances: just don't expect intricate technique. Ferland Mendy, potentially, could do enormous good at left-back: he's talented, defensive and athletic. But he's also a stimulus to Marcelo's (footballing) appetite too. Midfield, where they'll surely either add Pogba or Donny Van Der Beek, is where they still have significant shoring up to do.

Players they should sell: Now here's the rub! It's common knowledge that not only does Zidane want Gareth Bale out and that Florentino wants a hefty price for the Welshman, but too few realise that his contract is vastly lucrative and lengthy and that he's flat refusing to go. A terrific summer soap opera is brewing. Expect trouble ahead. It's also daft that Keylor Navas, on comparative form, not only isn't Madrid's No.1 keeper but is being pushed out. There's a bargain buy here for someone. Madrid must bite the bullet and decide that either Marco Asensio, Lucas Vazquez or Isco is surplus and can generate a huge price. Right now there is, as airlines would say, "overbooking" in Madrid's advanced positions, meaning time to take hard decisions. Frankly: they should have sold Toni Kroos. -- Graham Hunter

Rather than represent the final piece, the signing of Cristiano Ronaldo marked the beginning of a new growth phase with one eye on the Champions League and another on winning new fans and commercial deals all over the world. Juventus wish to make the most of his ability to attract the best talent of a new generation, the stars of which grew up watching him and find the idea of learning at his side very appealing. How they pay for these hype machines whose potential comes at a premium will be one of the things to watch over the course of the window.

The team needs to get younger particularly at the back. The midfield must also be skilled up with more passers and dribblers; this area, perhaps more than any other, has to come under review.

Players they need to sign: Juventus hope to rejuvenate the centre-back department with the brightest young player in the position, Matthijs de Ligt, and Merih Demiral, an absolute steal from Sassuolo who seriously impressed in his first six months in Italy. The upgrade in midfield is being addressed in classic Juve fashion with smart free transfers. Expect Adrien Rabiot to follow Aaron Ramsey, while talk of Paul Pogba and Sergej Milinkovic-Savic continues. Funding those deals and persuading Fiorentina to part with Federico Chiesa looks problematic.

Players on their way out:Andrea Barzagli has retired, freeing up a spot in defence. There is a leadership gap that needs bridging. The return of Gianluigi Buffon will compensate for that as well as the vacant backup goalkeeper slot, with Mattia Perin seeking regular game time ahead of the Euros. If players with big egos like Pogba, Rabiot and Mauro Icardi do arrive, Juventus will need Buffon to keep them all in check. A decision also needs to be made on what's best for Moise Kean's development.

Players they should sell: Gonzalo Higuain is proving hard to shift, and Sarri's arrival is unlikely to improve his cause with Cristiano Ronaldo taking over the No. 9 role. The same goes for Marko Pjaca. Remember him. Mario Mandzukic and Sami Khedira got their contracts extended last year but it's difficult to see a future for them. Paulo Dybala would almost certainly have pushed for a move in the event Allegri stayed. Cancelo is on his way out after just a year in Turin and while it's true Douglas Costa was one of the few players name-checked by Sarri in his introductory news conference, you'd think Juventus would sacrifice him in an effort to stack up the funds necessary for Chiesa. -- James Horncastle

After their frugal transfer market policy in 2017-18 failed to deliver in Europe (and only narrowly secured a seventh consecutive league title), the German champions are determined to spend heavily to create a team that can challenge in the Champions League once more. Their rebuilding project is mainly focussed on installing a new, pacier defence -- French World Cup winners Lucas Hernandez and Benjamin Pavard will replace 2014 World champions Mats Hummels and Jerome Boateng -- as well as adding more depth and class in central midfield and on the flanks, where Arjen Robben and Franck Ribery are no longer around to make the difference at elite level.

Finding affordable world-class attacking players willing to move to Bavaria and to work with the rather defensive-minded manager Niko Kovac has proved rather complicated, however, even for the wealthiest team in the Bundesliga. As things stand, Bayern might be forced to push forward the transfer of RB Leipzig's Timo Werner, who is out of contract next summer, as a versatile option up front. But the 23-year-old is not quite the marquee signing everyone is hoping for. With two months to go before the closing for the transfer window, murmurs of discontent over the lack of progress by sporting director Hasan Salihamidzic are getting louder.

Players they need to sign: Getting Leroy Sané or a comparable top quality winger is crucial as French international Kingsley Coman is too injury prone to provide a constant threat by himself on the left. There's also a need for a fourth centre-back, as Boateng is set to follow Hummels out of the door.

Players on their way out: If Bayern can bring in one more defensive central midfielder/deep-lying controller, they'd be willing to part company with Renato Sanches and perhaps Javier Martinez as well.

Players they should sell: Canadian teenager Alphonso Davies shouldn't be sold just yet but would be well served with getting more game time at another club on loan. -- Raphael Honigstein

PSG have made a very early move in this transfer market but not for a player; rather, they've changed their sporting director. Only time will tell if Leonardo will be as successful in his second spell as he was in his first (2011-2013), but the French champions had to do something about this key position. Now he's under pressure to strengthen the squad and balance the books. Players out of contract have already left (Adrien Rabiot, Dani Alves and Gianluigi Buffon), others have been sold (promising youngster Moussa Diaby and Giovani Lo Celso) and the likes of Timothy Weah, Christopher Nkunku, Presnel Kimpembe, Thomas Meaner and Layvin Kurzawa could follow.

Neymar's future is also very uncertain as PSG are keen to sell him. Parallel to the sales, the Parisians will buy. They will be quite active if they do sell well, too. They need more depth in their squad and they have been crying out for a very strong defensive midfielder. The idea is very much to build the team around Kylian Mbappé and associate him with top players.

Players they need to sign: Right now, what PSG need the most is a top defensive midfielder. It has been their main weakness for years. Napoli's Allan would be perfect, for example, and the club is working hard to make it happen. A centre-back is also needed, with Matthijs De Ligt the main target. On both deals, the club is confident.

Players on their way out:Edinson Cavani has only one year left on his current deal but the club will open talks soon to extend it, and deservedly so. Thiago Silva is in the same situation but the outcome could be very different as some people at the club are wondering if the 34-year-old Brazilian should be sold now.

Players they should sell: A few will leave, but Neymar is the one they should really sell. The project has not worked out for various reasons, and it's time to part ways. Both the club and the player want it. PSG will get a lot of money for him and can reinvest it while also easing FFP scrutiny too. -- Julien Laurens